This invention relates generally to structures involving the growth of epitaxial thin-films upon semiconductor-based materials and relates, more particularly, to such structures having thin films grown thereon which possess desirable ferroelectric properties.
It is known that a thin-film layer of a ferroelectric material, such as BaTiO.sub.3, can be grown directly upon a semiconductor-based material, such as silicon, to render a monolithic structure which possesses both semiconductor and ferroelectric properties. For example, applicants have described the growth of such a material in their co-pending application Ser. No. 08/692,343, filed Aug. 5, 1996, wherein the build up of the ferroelectric material directly upon a semiconductor-based material, such as silicon, is effected one-plane-at-a-time wherein each plane contains one of two selected constituent metal oxide planes of the crystalline form of the ferroelectric material.
Heretofore, however, there does not exist such a structure which incorporates a ferroelectric material and a silicon substrate wherein the ferroelectric material can be poled out-of-plane thereby enabling the in-plane switching of the underlying silicon. It would be desirable, therefore, to provide a monolithic structure comprised of a film of ferroelectric material disposed upon a semiconductor-based substrate, such as silicon, wherein the ferroelectric material is capable of being poled out-of-plane.
Accordingly, it is an object of the present invention to provide a structure wherein a ferroelectric thin film is disposed upon a semiconductor-based material, such as silicon, and wherein the thin film of ferroelectric material is capable of being poled out-of-plane and a method of treating and/or forming a ferroelectric thin film atop a semiconductor substrate which is capable of being poled out-of-plane.
Another object of the present invention is to provide such a structure wherein the geometric shape of the thin film of ferroelectric material advantageously affects the ferroelectric characteristics of the thin film.
Still another object of the present invention is to provide a structure whose ferroelectric thin film is comprised of a plurality of islands of thin film material disposed across the surface of the semiconductor-based material.